HETERODONTOSAURS

[darren.naish@port.ac.uk]

Michael de Sosa wrote...

> I'd appreciate if one of you wonderful people would elucidate any
> current thought on heterodontosaur relationships (phylogenetic, not
> romantic). How closely related are they to marginocephalians in
> particular? Other groups? They were just basal cerapodans the last
> time I checked. Any new specimens or species?

In the (in press) Pal. Ass. Isle of Wight dinosaur book, we (myself and 
David Martill) argue that heterodontosaurs are either the sister-taxon 
to Marginocephalia, or are marginocephalians (though on the basis of 
PT definitions this may not stand up). This is far from original - the 
idea has formerly been bandied around by Santa-Luca and several 
members of this list (see posts in the archives by Buchholz and others - 
do a search for 'heterodontosaurs and marginocephalians'), and was 
recently supported by Zhao et al. (1999) in their paper on 
_Chaoyangsaurus_. I've been pleasantly surprised to find that some 
prominent ornithischian workers are quite keen on the idea (and, 
surprisingly, we got an easy ride from reviewers on this bit!).

PS - _Marshosaurus_ in Europe? Stay tuned.

DARREN NAISH 
PALAEOBIOLOGY RESEARCH GROUP
School of Earth & Environmental Sciences
UNIVERSITY OF PORTSMOUTH
Burnaby Building
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